<!DOCTYPE html>
<html lang="zh">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      var uname = "admin",
        pwd = "123456"
      do {
        var uname1 = prompt("请输入用户名")
        do {
          var pwd1 = prompt("请输入密码")
        } while (pwd !== pwd1)
      } while (uname !== uname1)

      alert("登陆成功！")
    </script>
  </body>
</html>
